1. Field of the Invention
The invention relates to the isomerization of linalyl halides.
2. Brief Description of the Prior Art
It is known in the prior art to isomerize simple allylic halides, notably the dichlorobutenes, to their allylic isomers in the presence of a copper catalyst in combination with an organic quaternary salt (U.S. Pat. Nos. 3,819,730 to Nakata and 3,836,592 to Gordon). In spite of the availability of these known methods of isomerization, there has remained a need for economical processes, saving of energy and operating at lower temperatures, for isomerizing more complex allylic halides, notably linalyl chloride. The shortcomings of the prior art methods are evident when they are applied to the halides obtained by hydrohalogenation of myrcene, principally the linalyl halides. In particular, the use of elevated temperatures which leads to low yields because of extensive rearrangement of linalyl to terpinyl halides, an undesirable side reaction unique to the myrcene hydrohalides.
The method of the present invention is such an improvement over the prior art, requiring low temperatures and short isomerization times.